ICD-10 Code H21.4 – Pupillary membranes (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H21.4 – Pupillary membranes
What it is
Pupillary membranes are thin strands or sheets of tissue across the pupil, usually representing a residual developmental or acquired membrane in the anterior segment. They can partially block the visual axis or remain incidental.
Clinical signs
You may see a visible membrane crossing or covering part of the pupil on slit-lamp exam. Clinical features vary; refer to documentation for whether vision is affected, whether the membrane is stable, and whether it is congenital or acquired.
When to use this code
Use H21.4 when the provider documents pupillary membranes as the diagnosed condition. This code fits cases where the membrane is noted on eye examination, with or without visual disturbance. If the record only mentions another anterior segment abnormality, check documentation before assigning this code.
Do not use for
Do not use this code for iris adhesions, pupillary seclusion, or other distinct posterior or anterior synechiae unless the provider specifically documents pupillary membranes. If the finding is uncertain, check documentation.
Coding tip
Code from the ophthalmology note, and capture laterality or associated eye conditions only when documented.